STRUCTURAL ARRANGEMENT IN A LOW-TEMPERATURE TURBOCOMPRESSOR FOR AN INTERNAL COMBUSTION ENGINE

Abstract

 "The low-temperature turbocompressor structural arrangement for an internal combustion engine" is a system for using the energy that is available but unused during operation of an internal combustion engine to cool the air supplied to said engine by supercharging, applicable to internal combustion engines of any type. The temperature of the air compressed by the compressor is reduced by a cooling system and the air is then conveyed to a further turbine actuated by the intake air flow of the engine, affording the benefits of enhancing engine performance levels, which may be used in order to obtain greater power or reduce consumption, since the denser air allows more fuel into the combustion chamber, achieving greater combustion, which increases the power-to-weight ratio, and the cooler air allows work at more aggressive compression and/or ignition advance ratios without problems of pre-ignition/pinking, thereby enhancing engine performance levels. The structural arrangement may be mounted in full or in part, and also each component may be fitted into existing systems.

Description

[0001] The present invention relates to a structural arrangement in a low-temperature turbocompressor for an internal combustion engine, which is a system for using the energy that is available but unused during operation of an internal combustion engine for cooling the air supplied to said engine by supercharging.

[0002] Scope: The present structural arrangement in a low-temperature turbocompressor for an internal combustion engine can be used in any type of internal-combustion engine.

[0003] Prior art and problem: The prior art, and the reason for this patent, is the premise that both the torque and the efficiency of an engine are related to the mass of air that the engine can aspirate per intake cycle. Compressing the air before intake thereof into the engine increases the mass of air admitted into the cylinder, and consequently the fuel injection, thereby increasing the torque and therefore the power of the engine. This effect helps to reduce the size of a turbocharged engine in relation to a naturally aspirated engine, saving fuel and reducing mass and volume for the same power. The most common types of supercharging are mechanical compression and turbocompression. While mechanical compressors use some of the torque to increase the mass of air admitted by the engine, turbocompressors have the advantage of using energy that would otherwise be discharged into the environment through the exhaust pipe to achieve the same effect. A turbocompression system is formed by a turbine that uses the exhaust gases from the engine and that is rigidly connected to a compressor that compresses the air into the engine. However, the energy supplied to the turbine is sometimes greater than necessary, and pressure adjustment systems are required to ensure that the engine is only supplied with the necessary air, and at a safe pressure.

[0004] Both types of compressor are regulated by relief valves to work up to a pressure limit so as not to damage the engines to which the supercharging is applied. The adjustment system most commonly used in turbocompressors is a wastegate valve, which enables a portion of the exhaust gas to not pass through the turbine, thereby not increasing the energy transferred to the compressor. A pop-off valve can also be used, including in mechanical compressors, to eliminate the excess pressure in the system after the compressor by causing a sort of leak in the system when a predetermined pressure is reached. Another problem with compression is the consequent increase in the temperature of the air resulting in a reduction in density and an increase in the risk of abnormal combustion within the cylinders. To avoid these problems, vehicles that use this type of compression have to keep said compression within a safety limit, provide means for reducing the ignition advance, or use fuel of a higher octane than normal.

[0005] The devices used to minimize pinking are called intermediate coolers, or intercoolers. The intercooler is a heat exchanger used to reduce the temperature of the compressed air, increasing the density thereof and reducing the risk of abnormal combustion. Nonetheless, the inlet temperature remains high in relation to the ambient air, which is prejudicial for internal-combustion engines, in particular spark-ignition engines, which operate more efficiently at lower inlet temperatures. The issue is so important for internal-combustion engines that other devices are used in addition to the intercooler to reduce the risk of abnormal combustion, such as increasing the quantity of fuel in the mixture, injecting water along with the fuel or even, in the most extreme cases, using ice or cooling gas sprays along with the intercooler.

[0006] No references identical to the subject matter being proposed have been found in the patents of the Brazilian National Institute of Industrial Property (INPI). Patent PI 0412575-4 relates to the cooling of charge air with a secondary cooling circuit that can be liquid, since the problem of boiling is mentioned, and not recirculation of the intake gas itself, with turbines and compressors not connected in the same system, as in a conventional two-stage system.

[0007] Patents BR 102014010250-7 and PI 0603300-4 relate to the recirculation of exhaust gas, while the TCBT recirculates the fresh intake air.

[0008] Patent PI 1100859-8 has an adjustment valve at the intake of the engine, and does not have a turbine in the return. The adjustment and relief valves are also separated and there is no reference to the return from the relief to the compressor.

[0009] Inventive concept: In view of this problem, the present structural arrangement in a low-temperature turbocompressor for an internal combustion engine incorporates the following innovations and functions:

[0010] The present structural arrangement in a low-temperature turbocompressor for an internal combustion engine incorporates the concept of supercharging of the internal-combustion engine by the compressor with pressures up to the maximum limit of the latter, unlike the usual arrangement in which the pressure inside the system is kept practically constant by adjustment systems, from the outlet of the compressor to the inlet valves of the engine. The temperature of the air compressed by the compressor is reduced by a cooling system and is then conveyed to a further turbine driven by the flow of intake air of the engine. The main innovation of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine described herein is to supply the engine with air that is colder and therefore denser than a common turbocompressor, and to do so using the same amount of energy as consumed by the latter. The benefits resulting from this are enhanced engine performance levels, which may be used in order to obtain greater power or reduce consumption, since the denser air contains more oxygen and allows more fuel into the combustion chamber at the same pressure, achieving a larger explosion, which increases the power-to-weight ratio, and the cooler air allows work at more aggressive compression ratios and/or ignition advances without problems of pre-ignition/pinking, thereby enhancing engine performance.

[0011] The present structural arrangement in a low-temperature turbocompressor for an internal combustion engine can be installed fully or partially, as required or to order.

[0012] Each component of the present structural arrangement in a low-temperature turbocompressor for an internal combustion engine can be adapted to preexisting systems.

[0013] Advantages: The advantages of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine are as follows:

[0014] It enables the engine to be supplied with air that is colder and therefore denser than a common turbocompressor, using the same amount of energy as consumed by this latter.

[0015] It enables more fuel to be conveyed to the combustion chamber and enables a larger explosion, which increases the power-to-weight ratio.

[0016] It enables the engine to operate with higher compression ratios and/or greater ignition advance without causing problems of abnormal combustion, which increases the performance of the engine.

[0017] The turbocompressor only connects to the cooled-air turbine system once said turbines have started to generate power for the system.

[0018] Drawings: In order to facilitate the search and understanding of the present patent, as recommended in the report, according to a basic and preferred embodiment created by the applicant, reference is made to the attached drawing, which supplements and supports the present description, in which:

Figure 1 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with just one compression stage.

Figure 2 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with an additional low-pressure turbocompressor arranged in parallel.

Figure 3 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with an additional low-pressure turbocompressor arranged in parallel and an additional intercooler.

Figure 4 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with an additional high-pressure turbocompressor arranged in parallel.

Figure 5 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with an additional low-pressure turbocompressor on the same shaft.

Figure 6 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with an additional mechanical compressor.

Figure 7 - Schematic view of alternative inversions of the sequence of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine. (A) Inversion of the sequence between the return gas and intake gas turbines; (B) between the exhaust turbine and the compressor.

Figure 8 - Schematic view of alternative arrangements of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine. (A) Assembly perpendicular to the cold turbines; (B) assembly parallel to the cold turbines.

Figure 9 - Schematic view of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine with a coupling/uncoupling system for the cold turbines. (A) dependent; (B) independent.

[0019] Unbroken line 1-7: intake pipe
Dotted line 5-6: Return pipe
Dashed line 8-9: Exhaust pipe
T1 - Exhaust gas turbine
C - Compressor
T2 - Return gas turbine
T3 - Intake gas turbine
IC - Intercooler
IC' - Additional intercooler
V - Return valve
M - Engine
T' - Additional turbine
C' - Additional compressor

[0020] Description: In the structural arrangement in a low-temperature turbocompressor for an internal combustion engine (figure 1), the turbocompression system is formed by the exhaust gas turbine (T1) rigidly connected to the compressor (C). The compressor conveys the fluid to a cooler that can be an intercooler (IC), but that is not limited to this or other types of heat exchangers, nor to a specific coolant fluid, since any type of coolant fluid can used. Sequentially, the flow of cooled compressed air is conveyed to a second turbine, known as the intake gas turbine (T3), the pressure of which is regulated by a return valve (V) that prevents the overloading of the engine (M), directing the excess flow to a third turbine, known as the return gas turbine (T2), which returns the air to the inlet of the compressor (C). The two turbines T2 and T3 are rigidly connected to the compressor (C) and to the exhaust gas turbine (T1). The system can use compressors and turbines of variable geometry and any other compressors or turbines that can be installed on the same shaft, with any type of assembly constraining the movement thereof. The system can also include multiple stages with turbocompressors on separate shafts or on the same shaft as the former. The system proposed in the structural arrangement in a low-temperature turbocompressor for an internal combustion engine can also be used in conjunction with other air compressors, mechanical (figure 6) or otherwise, or even with additional turbocompressors, all in series (figure 5) or in parallel (figures 2, 3 and 4) with the first. The system can also be used with compressors and turbines of variable geometry, with multiple stage expansion and/or compression. The engine can be a two- or four-stroke Otto-cycle or diesel engine. Additional heat exchangers can also be used, and any coolant fluid can be used.

[0021] Figure 1 shows operation of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine, in which the turbocompression system is formed by the exhaust gas turbine (T1), which uses the exhaust gases from the engine that are flowing through the exhaust pipe (dashed line) and is rigidly connected to the compressor (C). The temperature of the air in this compressor (C), which is arranged at the start of the intake pipe (unbroken line), is lowered by the intercooler cooling system (IC), after which the air is conveyed to the intake gas turbine (T3), moved by the flow of intake air of the engine. The pressure is regulated by the return valve (V), which releases some of the compressed air to ensure that the pressure does not exceed the maximum pressure admitted by the engine (M). The air released by this valve is conveyed through the return pipe (dotted line) to the return gas turbine (T2), which expands this mass of air from the working pressure of the engine to atmospheric pressure, resulting in a loss of heat. This air is conveyed to the inlet of the compressor (C) as part of the air that is compressed in the cycle, reducing the work done by the compressor on account of the low temperature thereof. The turbines moved by compressed air are constrained to move with the compressor (C) to generate more power and to enable the compressor (C) to produce even greater pressures. The cycle is therefore fed back by the work of the compressed-air turbines (the return gas turbine (T2) and the intake gas turbine (T3)) and by the lower effort required by the compressor (C) to compress the cooler air, tending to reach an equilibrium resulting from mechanical and thermal losses. Therefore, the objective of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine is to cause the temperature of the intake air of the engine, at a given working pressure of the engine, to be significantly lower than the temperature reached in a normal system.

[0022] To achieve this purpose, other configurations of the structural arrangement in a low-temperature turbocompressor for an internal combustion engine are possible, as shown in figures 2, 3, 4, 5, 6, 7 and 8. Figures 2 and 3 relate to the installation of an additional low-pressure turbocompressor in parallel with the turbocompressor formed by the exhaust gas turbine (T1) and the compressor (C). In these configurations, an additional turbine (T') installed in the exhaust pipe uses the exhaust gases from the engine after the exhaust gas turbine (T1) to drive a constrained additional compressor (C') installed in the intake pipe before the compressor (C), increasing air intake. In figure 3, the air coming from the additional compressor (C') is cooled by an additional intercooler (IC') before entering the compressor (C). Figure 4 relates to the installation of an additional high-pressure turbocompressor in parallel with the turbocompressor formed by the exhaust gas turbine (T1) and the compressor (C) . In this configuration, an additional turbine (T') installed in the exhaust pipe uses the exhaust gases from the engine before the exhaust gas turbine (T1) to drive a constrained additional compressor (C') installed in the intake pipe between the compressor (C) and the intercooler (IC), also to increase air intake. Figure 5 relates to the installation of an additional high-pressure turbocompressor on the same shaft as the other turbocompressors. In this configuration, an additional turbine (T') installed in the exhaust pipe uses the exhaust gases from the engine after the exhaust gas turbine (T1) to drive an additional compressor (C') rigidly connected to the system, installed in the intake pipe before the compressor (C), also to increase air intake. Figure 6 relates to the installation of an additional mechanical compressor (C') arranged in parallel with the turbocompressor formed by the exhaust gas turbine (T1) and the compressor (C). In this configuration, an additional constrained mechanical compressor (C') is installed on the intake pipe between the intake gas turbine (T3) and the engine (M), also to increase air intake. Figures 7 and 8 show other possible configurations intended to take advantage of available spaces and/or conditions. Figure 7A shows the installation of the intake gas turbine (T3) between the compressor (C) and the return gas turbine (T2), bringing the first turbine of the intercooler (IC) closer. Figure 7B shows the option of placing the exhaust gas turbine (T1) in sequence with the return gas turbine (T2) and intake gas turbine (T3) positioned on the shaft after the compressor. Figure 8 shows an example of the rotational transmission options from the return gas turbine (T2) and intake gas turbine (T3) to the compressor (C), perpendicularly using gears (A) or in parallel using a belt (B).

[0023] Figure 9 explores the possibility of using a coupling system that enables the turbocompressor formed by the exhaust gas turbine (T1) and the compressor (C) to only connect to the system of the return gas turbine (T2) and the intake gas turbine (T3) when said turbines start generating power for the system. In configuration "A" in figure 9, the coupling occurs when the system of the return gas turbine (T2) and the intake gas turbine (T3) in conjunction begins generating power for the system, and configuration "B" in figure 9 provides the option of the return gas turbine (T2) being coupled when said turbine starts generating power for the system, followed by coupling of the intake gas turbine (T3) when said turbine reaches the required state.

[0024] Conclusion: Accordingly, the structural arrangement in a low-temperature turbocompressor for an internal combustion engine is based on novel functional and technical features, as can be seen from the attached figures and understood from the description, thereby qualifying for the claimed legal protection.

Claims

1. "The low-temperature turbocompressor structural arrangement for an internal combustion engine" relates to a system for using the energy that is available but unused during operation of an internal combustion engine to cool the air supplied to said engine by supercharging, applicable to internal combustion engines of any type, characterized in that it supplies the engine with air that is colder and therefore denser than a common turbocompressor, and does so using the same amount of energy as consumed by this latter.

2. "The low-temperature turbocompressor structural arrangement for an internal combustion engine" relates to a system for using the energy that is available but unused during operation of an internal combustion engine to cool the air supplied to said engine by supercharging, applicable to internal combustion engines of any type, as described in 001, formed by a system comprising a turbocompressor and turbines and characterized in that the turbocompression system is formed by the exhaust gas turbine (T1) rigidly connected to the compressor (C), in which said compressor conveys the fluid to a fluid cooler that can be an intercooler (IC), but that is not limited to this or other types of heat exchanger, nor to a specific coolant fluid, since any type can be used, and sequentially, the flow of cooled compressed air is conveyed to an intake gas turbine (T3) with pressure regulated by a return valve (V) that prevents the overloading of the engine (M) and directs the excess flow to a return gas turbine (T2) that returns the air to the inlet of the compressor (C), in which the turbines T2 and T3 are rigidly connected to the compressor (C) and to the exhaust gas turbine (T1).

3. "The low-temperature turbocompressor structural arrangement for an internal combustion engine" relates to a system for using the energy that is available but unused during operation of an internal combustion engine to cool the air supplied to said engine by supercharging, applicable to internal combustion engines of any type, as described in 1 and 2, with alternative structures characterized in that the system can use compressors and turbines of variable geometry or any other compressors or turbines that can be installed on the same shaft, with any type of assembly constraining the movement thereof, include multiple stages with turbocompressors on separate shafts or on the same shaft as the first, be used in conjunction with other air compressors, mechanical (figure 6) or otherwise, or even with additional turbocompressors, all in series (figure 5) or in parallel (figures 2, 3 and 4) with the former, use compressors and turbines of variable geometry, with multiple stage expansion and/or compression, in two- or four-stroke Otto-cycle or diesel engines, using additional heat exchangers and any coolant fluid, with the option of assembling fully or partially as required, in which each component part can be adapted to pre-existing systems.

4. "The low-temperature turbocompressor structural arrangement for an internal combustion engine" relates to a system for using the energy that is available but unused during operation of an internal combustion engine to cool the air supplied to said engine by supercharging, applicable to internal combustion engines of any type, as described in 1, 2 and 3, with connection of the turbocompressor to the system of cooled air turbines, characterized in that they occur, but not exclusively, from the moment at which said turbines begin generating power for the system, individually or in a group (figure 9) .

Drawing